Evaporator with cool storage function

ABSTRACT

An evaporator with a cool storage function includes a plurality of refrigerant flow tubes, fins, and cool storage material containers. Each of the cool storage material containers has a longitudinal direction and includes a third side wall and a fourth side wall opposite to the third side wall. The third side wall and the fourth side wall have first convex portions and second convex portions, respectively. The cool storage material containers are provided in a second part of spaces such that the first convex portions contact a first side wall of one of the plurality of refrigerant flow tubes and the second convex portions contact a second side wall of another of the plurality of refrigerant flow tubes. The third side wall and the fourth side wall have a concavo-convex shape in a cross-section perpendicular to the longitudinal direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of the U.S. patentapplication Ser. No. 12/998,784 filed Jun. 1, 2011, which in turn is anational stage application of International Application No.PCT/JP2009/071211, filed Dec. 21, 2009, which claims priority toJapanese Patent Application No.2008-332921, filed Dec. 26, 2008. Thecontents of these applications are incorporated herein by reference intheir entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an evaporator with a cool storagefunction.

2. Discussion of the Background

In recent years, in order to protect the environment and improve fuelconsumption of automobiles, there has been proposed an automobiledesigned to automatically stop the engine when the automobile stops, forexample, so as to wait for a traffic light to change.

Incidentally, an ordinary car air conditioner has a problem in that,when an engine of an automobile in which the air conditioner is mountedis stopped, a compressor driven by the engine is stopped, and supply ofrefrigerant to an evaporator stops, whereby the cooling capacity of theair conditioner sharply drops.

As one measure to solve such a problem, imparting a cool storagefunction to the evaporator has been considered, to thereby enablecooling of a vehicle compartment by making use of cool stored in theevaporator, when the compressor stops as a result of stoppage of theengine.

An evaporator having a cool storage function has been proposed (seeJapanese Patent No. 4043776). The proposed evaporator includes aplurality of flat refrigerant flow tube sections disposed in parallelsuch that their width direction coincides with an air flow direction,and they are spaced from one another; and hollow cool storage materialcontainers each of which is fixedly provided on one side of acorresponding refrigerant flow tube section and contains a cool storagematerial therein. A plurality of sets each composed of a refrigerantflow tube section and a cool storage material container are provided atpredetermined intervals along the longitudinal direction of headersections. Fins are disposed between adjacent sets each composed of arefrigerant flow tube section and a cool storage material container.

According to the evaporator having a cool storage function disclosed inJapanese Patent No. 4043776, a low temperature refrigerant flowingthrough the refrigerant flow tube sections enables storage of cool inthe cool storage material within the cool storage material containers.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, an evaporator with acool storage function includes a plurality of refrigerant flow tubes,fins, and cool storage material containers. The plurality of refrigerantflow tubes each have a first side wall and a second side wall oppositeto the first side wall and are provided to form spaces between the firstside wall and the second side wall such that the first side wall of oneof the plurality of refrigerant flow tubes faces the second side wall ofanother of the plurality of refrigerant flow tubes. The spaces have afirst part and a second part other than the first part. The fins areprovided in the first part of the spaces. The cool storage materialcontainers contain a cool storage material. Each of the cool storagematerial containers has a longitudinal direction and includes a thirdside wall and a fourth side wall opposite to the third side wall. Thethird side wall and the fourth side wall have first convex portions andsecond convex portions, respectively. The cool storage materialcontainers are provided in the second part of the spaces such that thefirst convex portions contact the first side wall of the one of theplurality of refrigerant flow tubes and the second convex portionscontact the second side wall of the another of the plurality ofrefrigerant flow tubes. The third side wall and the fourth side wallhave a concavo-convex shape in a cross-section perpendicular to thelongitudinal direction.

According to another aspect of the present invention, an evaporator witha cool storage function includes a plurality of refrigerant flow tubes,fins, and cool storage material containers. The plurality of refrigerantflow tubes each have a first side wall and a second side wall oppositeto the first side wall and are provided to form spaces between the firstside wall and the second side wall such that the first side wall of oneof the plurality of refrigerant flow tubes faces the second side wall ofanother of the plurality of refrigerant flow tubes. The spaces have afirst part and a second part other than the first part. The fins areprovided in the first part of the spaces. The cool storage materialcontainers contain a cool storage material. Each of the cool storagematerial containers has a longitudinal direction and includes a thirdside wall and a fourth side wall opposite to the third side wall. Thethird side wall has a plurality of first convex portions arranged in thelongitudinal direction. The fourth side wall has a plurality of secondconvex portions arranged in the longitudinal direction. The cool storagematerial containers are provided in the second part of the spaces suchthat the first convex portions contact the first side wall of the one ofthe plurality of refrigerant flow tubes and the second convex portionscontact the second side wall of the another of the plurality ofrefrigerant flow tubes. A plurality of first paths are formed betweenthe third side wall and the first side wall of the one of the pluralityof refrigerant flow tubes to be arranged in the longitudinal direction.A plurality of second paths are formed between the fourth side wall andthe second side wall of the another of the plurality of refrigerant flowtubes to be arranged in the longitudinal direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the overall structure of anevaporator with a cool storage function according to an embodiment ofthe present invention.

FIG. 2 is an enlarged sectional view taken along line A-A of FIG. 1.

FIG. 3 is a perspective view showing cool storage material containersand a communication member.

DESCRIPTION OF THE EMBODIMENTS

An embodiment of the present invention will next be described withreference to the drawings.

In the following description, the downstream side (a directionrepresented by arrow X in FIG. 1) with respect to an air flow directionwill be referred to as the “front,” and the opposite side as the “rear.”Further, the upper, lower, left-hand, and right-hand sides as viewedrearward from the front side; i.e., the upper, lower, left-hand, andright-hand sides of FIG. 1, will be referred to as “upper,” “lower,”“left, and “right,” respectively.

In the following description, the term “aluminum” encompasses aluminumalloys in addition to pure aluminum.

FIG. 1 shows the overall configuration of an evaporator with a coolstorage function according to the embodiment of the present invention,and FIGS. 2 and 3 show the configurations of essential portions of theevaporator.

As shown in FIGS. 1 and 2, an evaporator with a cool storage function(1) includes a first header tank (2) and a second header tank (3) formedof aluminum and disposed apart from each other in the vertical directionsuch that they extend in the left-right direction; and front and rearrefrigerant flow tube rows (4A) and (4B) provided between the two headertanks (2) and (3) such that they are spaced from each other in thefront-rear direction.

The first header tank (2) includes a refrigerant inlet header section(5) located on the front side (downstream side with respect to the airflow direction); and a refrigerant outlet header section (6) located onthe rear side (upstream side with respect to the air flow direction) andunited with the refrigerant inlet header section (5). A refrigerantinlet (7) is provided at the right end of the refrigerant inlet headersection (5), and a refrigerant outlet (8) is provided at the right endof the refrigerant outlet header section (6). The second header tank (3)includes a first intermediate header section (9) located on the frontside, and a second intermediate header section (11) located on the rearside and united with the first intermediate header section (9). Therespective interiors of the first and second intermediate headersections (9) and (11) of the second header tank (3) are connectedtogether by means of unillustrated proper means.

The front refrigerant flow tube row (4A) is composed of a plurality offlat refrigerant flow tubes (12) (refrigerant flow tube sections) formedof aluminum extrudate. The refrigerant flow tubes (12) are disposedbetween the refrigerant inlet header section (5) of the first headertank (2) and the first intermediate header section (9) of the secondheader tank (3) such that their width direction coincides with thefront-rear direction and they are spaced from each other in theleft-right direction. Upper and lower end portions of the refrigerantflow tubes (12) are brazed to the upper and lower header tanks (2) and(3), respectively. The rear refrigerant flow tube row (4B) is composedof a plurality of flat refrigerant flow tubes (12) (refrigerant flowtube sections) formed of aluminum extrudate. The refrigerant flow tubes(12) are disposed between the refrigerant outlet header section (6) ofthe first header tank (2) and the second intermediate header section(11) of the second header tank (3) such that their width directioncoincides with the front-rear direction and they are spaced from eachother in the left-right direction. Upper and lower end portions of therefrigerant flow tubes (12) are brazed to the upper and lower headertanks (2) and (3), respectively. Each refrigerant flow tube (12) of thefront refrigerant flow tube row (4A) is located at the same position(with respect to the left-right direction) as the correspondingrefrigerant flow tube (12) of the rear refrigerant flow tube row (4B).Air-passing clearances (13) and (13A) are formed between the refrigerantflow tubes (12) of the front refrigerant flow tube row (4A) which areadjacent to one another in the left-right direction, and between therefrigerant flow tubes (12) of the rear refrigerant flow tube row (4B)which are adjacent to one another in the left-right direction.

Cool storage material containers (14) formed aluminum and filled with acool storage material (not shown) are disposed in a plurality of frontair-passing clearances (13A) among all the front air-passing clearances(13) and (13A) of the front refrigerant flow tube row (4A) and in aplurality of rear air-passing clearances (13A) of all the rearair-passing clearances (13) and (13A) of the rear refrigerant flow tuberow (4B), the front air-passing clearances (13A) being located at thesame positions as the corresponding rear air-passing clearances (13A).Each cool storage material container (14) is disposed to extend acrossthe air-passing clearances (13A) of the front and rear refrigerant flowtube rows (4A) and (4B), and is brazed (joined) to the correspondingrefrigerant flow tubes (12) of the front and rear refrigerant flow tuberows (4A) and (4B), which tubes are located on the left and right sidesof the cool storage material container (14). Corrugated fins (15) formedfrom an aluminum brazing sheet having a brazing material layer on eachof opposite sides thereof are disposed in the remaining air-passingclearances (13) and are brazed to the corresponding refrigerant flowtubes (12). Furthermore, corrugated fins (15) formed from an aluminumbrazing sheet having a brazing material layer on each of opposite sidesthereof are disposed on the outer sides of the refrigerant flow tubes(12) located at the left-hand and right-hand ends, respectively, and arebrazed (joined) to the corresponding refrigerant flow tubes (12).Moreover, side plates (16) formed of aluminum are disposed on the outersides of the corrugated fins (15) located at the left-hand andright-hand ends, respectively, and are brazed to the correspondingcorrugated fins (15).

As shown in FIGS. 2 and 3, each of the cool storage material containers(14) is composed of left and right side plates (17), a top plate (18),and a bottom plate (19). The left and right side plates (17) are formedby performing press work on an aluminum brazing sheet having a brazingmaterial layer on each of opposite sides thereof, and front and rearedge portions of the left and right side plates (17) are brazed togetheralong the entire length. The top plate (18) is formed by performingpress work on an aluminum brazing sheet having a brazing material layeron each of opposite sides thereof, and is brazed to the upper ends ofthe left and right side plates (17). The bottom plate (19) is formed byperforming press work on an aluminum brazing sheet having a brazingmaterial layer on each of opposite sides thereof, and is brazed to thelower ends of the left and right side plates (17). Portions of the leftand right side plates (17), excluding the front and rear edge portionsthereof brazed tighter, are bulged outward with respect to theleft-right direction so as to form outward bulging portions (21) whichextend in the vertical direction, whereby a cool storage materialcharging space (22) is formed between the left and right side plates(17). The cool storage material charging space (22) extends in thevertical direction, and has opened upper and lower ends. The upper endopening of the cool storage material charging space (22) is closed bythe top plate (18), and the lower end opening of the cool storagematerial charging space (22) is closed by the bottom plate (19).Preferably, a water-based cool storage material and a paraffin-basedcool storage material having an adjusted freezing point of about 3 to10° C. is charged into the cool storage material containers (14).Notably, in order to suppress variation in the temperature of dischargedair when cooling is performed by only the cool storage material chargedin all the cool storage material containers (14) and in order toincrease the amount of the cool storage material charged in the coolstorage material containers (14), preferably, three to seven air-passingclearances (13) (corrugated fins (15)) are present between the coolstorage material containers (14) adjacent to each other in theleft-right direction.

Preferably, the total of the air-flow-direction-upstream-side(rear-side) opening areas of the plurality of air-passing clearances(13A), in which the cool storage material containers (14) are disposed,is 5 to 30% the effective core area. Herein and in the claims, the term“effective core area” means the product of the shortest distance betweenthe first and second header tanks (2) and (3) as measured in thevertical direction, and the shortest distance between the outer edgeportions of the left-end and right-end corrugated fins (15) as measuredin the left-right direction. When the total of theair-flow-direction-upstream-side opening areas of the plurality ofair-passing clearances (13A), in which the cool storage materialcontainers (14) are disposed, is less than 5% the effective core area,the amount of the cool storage material charged in the cool storagematerial containers (14) becomes insufficient, and the cool storageeffect becomes insufficient. When the total of theair-flow-direction-upstream-side opening areas of the plurality ofair-passing clearances (13A), in which the cool storage materialcontainers (14) are disposed, exceeds 30% the effective core area,air-passage resistance may increase considerably.

A plurality of outward projecting convex portions (23) are formed onbudging-side top wall (21 a) of the outward bulging portion (21) of eachof the left and right side plates (17) of each cool storage materialcontainer (14), by means of deforming the budging-side top wall (21 a).The convex portions (23) extend in the vertical direction, and inclinefrontward toward the upper side, and are arrayed in the vertical andfront-rear directions. The projecting end portions of the convexportions (23) have flat surfaces. The projecting end portions of aplurality of convex portions (23) located at a front end portion of eachcool storage material container (14) and arrayed in the verticaldirection are brazed to the outer surfaces of the correspondingrefrigerant flow tubes (12) of the front refrigerant flow tube row (4A).Similarly, the projecting end portions of a plurality of convex portions(23) located at a rear end portion of each cool storage materialcontainer (14) and arrayed in the vertical direction are brazed to theouter surfaces of the corresponding refrigerant flow tubes (12) of therear refrigerant flow tube row (4B). Accordingly, gaps (“paths”) (24)for air passage and water drain are formed between the cool storagematerial containers (14) and the refrigerant flow tubes (12) atlocations where the cool storage material containers (14) and therefrigerant flow tubes (12) are brazed together. Notably, preferably,the shortest distance between the projecting end portions of the convexportions (23) of the left side plate (17) and the projecting endportions of the convex portions (23) of the right side plate (17), asmeasured in the left-right direction, is set to 5 to 11 mm. When theshortest distance is less than 5 mm, the amount of the cool storagematerial charged in the cool storage material containers (14) becomesinsufficient, and the cool storage effect becomes insufficient. When theshortest distance exceeds 11 mm, air-passage resistance may increaseconsiderably.

The interiors of all the cool storage material containers (14) areconnected together via a hollow communication member (25) which isformed of aluminum and which is sealed entirely. The communicationmember (25) includes a trunk portion (26) extending in the left-rightdirection, and branch portions (27) which are equal in number to thecool storage material containers (14) and which are provided on thetrunk portion (26) such that the branch portions (27) are spaced fromone another in the left-right direction, and extend rearward. A throughhole (not shown) is formed in a lower wall of a rear end portion of eachbranch portion (27), and the lower wall of each branch portion (27) isbrazed to the top plate (18) of the corresponding cool storage materialcontainer (14) such that the through hole communicates with a throughhole (not shown) formed in the top plate (18). A cool storage materialcharging port (28) is provided on the trunk portion (26) of thecommunication member (25). The cool storage material charging port (28)is closed after the cool storage material has been charged into all thecool storage material containers (14).

The above-described evaporator (1) with a cool storage functionconstitutes a car air conditioner in combination with a compressordriven by an engine of a vehicle, a condenser (refrigerant cooler) forcooling the refrigerant discharged from the compressor, and an expansionvalve (pressure-reducing unit) for reducing the pressure of therefrigerant having passed through the condenser. In the car airconditioner, when the compressor is operating, low pressure, two-phaserefrigerant (a mixture of vapor refrigerant and liquid refrigerant)having been compressed by the compressor and having passed through thecondenser and the expansion valve passes through the refrigerant inlet(7), and enters the inlet header section (5) of the evaporator (1). Therefrigerant then passes through the refrigerant flow tubes (12) of thefront refrigerant flow tube row (4A), and enters the first intermediateheader section (9). The refrigerant having entered the firstintermediate header section (9) enters the second intermediate headersection (11). After that, the refrigerant passes through the refrigerantflow tubes (12) of the rear refrigerant flow tube row (4B), enters theoutlet header section (6), and flows out via the refrigerant outlet (8).When the refrigerant flows through the refrigerant flow tubes (12), therefrigerant performs heat exchange with air (see arrow X in FIGS. 1 and2) passing through the air-passing clearances (13) (among theair-passing clearances (13) and (13A)) in which the cool storagematerial containers (14) are not disposed, and flows out of therefrigerant flow tubes (12) in a vapor phase.

At that time, the cool storage material charged in each cool storagematerial container (14) is cooled by the refrigerant flowing through therefrigerant flow tubes (12) which are located on the opposite sides ofthe cool storage material container (14) and form the air-passingclearance (13A) in which the cool storage material container (14) isdisposed. As a result, the cool storage material is frozen, whereby coolis stored therein. At that time, condensed water produced on surfaces(facing the cool storage material container (14)) of the refrigerantflow tubes (12) which are located on the opposite sides of the coolstorage material container (14) and form the air-passing clearance (13A)in which the cool storage material container (14) is disposed is drainedthrough the gaps (24) formed between the cool storage material container(14) and the refrigerant flow tubes (12) located on the opposite sidesof the cool storage material container (14).

When the compressor stops, the cool stored in the cool storage materialwithin each cool storage material container (14) is transferred to windpassing through the air-passing clearances (13) in which the corrugatedfins (15) are present via the refrigerant flow tubes (12) located on theopposite sides of the cool storage material container (14). Further, thecool stored in the cool storage material within each cool storagematerial container (14) is transferred to wind passing through the gaps(24) between the cool storage material container (14) and therefrigerant flow tubes (12) located on the opposite sides thereof.Accordingly, even when the temperature of wind having passed through theevaporator (1) increases, the wind is cooled by the cool storagematerial containers (14), so that a sharp drop in the cooling capacitycan be prevented.

In the above-described embodiment, the evaporator with a cool storagefunction may be a so-called laminated-type evaporator; i.e., anevaporator configured in which a plurality of flat hollow bodies eachcomposed of a pair of dish-shaped plates which faces each other and arebrazed together along the circumferential edges thereof are disposed inparallel, and the hollow bodies have refrigerant flow tube sectionsdisposed in parallel such that their width direction coincides with theair flow direction and they are spaced from one another, and refrigerantheader sections communicating with opposite end portions of therefrigerant flow tube sections; i.e., the refrigerant flow tube sectionsand the refrigerant header sections are unitarily provided.

The embodiment of the present invention includes the following modes.

1) An evaporator with a cool storage function which includes a pluralityof flat refrigerant flow tube sections disposed in parallel such thattheir width direction coincides with an air flow direction and they arespaced from one another, wherein air-passing clearances are formedbetween adjacent refrigerant flow tube sections, cool storage materialcontainers filled with a cool storage material are disposed in some ofall the air-passing clearances, and fins are disposed in the remainingair-passing clearances.

2) An evaporator with a cool storage function according to par. 1),wherein each cool storage material container includes a plurality ofconvex portions projecting outward from opposite side surfaces thereof,and projecting ends of the convex portions are joined to thecorresponding refrigerant flow tube sections.

3) An evaporator with a cool storage function according to par. 1),wherein the total of air-flow-direction-upstream-side opening areas ofthe air-passing clearances in which the cool storage material containersare disposed is 5 to 30% an effective core area.

4) An evaporator with a cool storage function according to par. 1),wherein the interiors of a plurality of cool storage material containersare connected with one another; and a cool storage material chargingport is provided in one of the cool storage material containersconnected with one another.

5) An evaporator with a cool storage function according to par. 1),wherein the interiors of all the cool storage material containers areconnected with one another via a communication member; and a coolstorage material charging port is provided on the communication memberor one of the cool storage material containers.

According to the evaporator with a cool storage function of par. 1),cool storage material containers filled with a cool storage material aredisposed in some of all the air-passing clearances, and fins aredisposed in the remaining air-passing clearances. Therefore, even whenthe effective core area is made equal to that of the evaporator with acool storage function described in Japanese Patent No. 4043776, thenumber of the refrigerant flow tube sections does not decreases.Accordingly, a drop in cooling performance can be suppressed.Furthermore, since the cool storage material containers are joined tothe refrigerant flow tube sections, a low temperature refrigerantflowing through the refrigerant flow tube sections enables storage ofcool in the cool storage material within the cool storage materialcontainers. Therefore, cool can be efficiently stored in the coolstorage material.

According to the evaporator with a cool storage function of par. 2),each cool storage material container includes a plurality of convexportions projecting outward from opposite side surfaces thereof, andprojecting ends of the convex portions are joined to the correspondingrefrigerant flow tube sections. Therefore, even at the air-passingclearances in which the cool storage material containers are disposed,the convex portions form gaps between the refrigerant flow tube sectionsand the cool storage material containers, so that air flows through thegaps. Accordingly, an increase in air-passage resistance can besuppressed. Furthermore, condensed water produced on the outer surfacesof the refrigerant flow tube sections can be drained through the gapsformed between the refrigerant flow tube sections and the cool storagematerial containers due to presence of the convex portions enables.

According to the evaporator with a cool storage function of par. 3), itis possible to suppress an increase in air-passage resistance, whilesecuring the effect of storing cool in the cool storage material chargedin the cool storage material containers. That is, when the total ofair-flow-direction-upstream-side opening areas of the air-passingclearances in which the cool storage material containers are disposed isless than 5% the effective core area, the amount of the cool storagematerial charged in the cool storage material containers becomesinsufficient, and the cool storage effect becomes insufficient. When thetotal of air-flow-direction-upstream-side opening areas of theair-passing clearances in which the cool storage material containers aredisposed exceeds 30% the effective core area, the air-passage resistancemay increase considerably.

According to the evaporator with a cool storage function of par. 4), thecool storage material can be charged into the plurality of cool storagematerial containers connected with one another, from the cool storagematerial charging port provided in one of the cool storage materialcontainers. Therefore, an operation of charging the cool storagematerial becomes simple, and overall manufacturing work is facilitated.

According to the evaporator with a cool storage function of par. 5), thecool storage material can be charged into all the cool storage materialcontainers from the cool storage material charging port provided on thecommunication member. Therefore, an operation of charging the coolstorage material becomes simple, and overall manufacturing work isfacilitated.

What is claimed is:
 1. An evaporator with a cool storage function,comprising: a plurality of refrigerant flow tubes each having a firstside wall and a second side wall opposite to the first side wall andprovided to form spaces between the first side wall and the second sidewall such that the first side wall of one of the plurality ofrefrigerant flow tubes faces the second side wall of another of theplurality of refrigerant flow tubes, the spaces having a first part anda second part other than the first part; fins provided in the first partof the spaces; cool storage material containers containing a coolstorage material, each of the cool storage material containers having alongitudinal direction and including a third side wall and a fourth sidewall opposite to the third side wall, the third side wall and the fourthside wall having first convex portions and second convex portions,respectively, the cool storage material containers being provided in thesecond part of the spaces such that the first convex portions contactthe first side wall of the one of the plurality of refrigerant flowtubes and the second convex portions contact the second side wall of theanother of the plurality of refrigerant flow tubes, the third side walland the fourth side wall having a concavo-convex shape in across-section perpendicular to the longitudinal direction.
 2. Theevaporator according to claim 1, wherein the first convex portions arebrazed to the first side wall of the one of the plurality of refrigerantflow tubes and the second convex portions are brazed to the second sidewall of the another of the plurality of refrigerant flow tubes.
 3. Theevaporator according to claim 1, wherein a number of the first partprovided between the second part and the second part is 3 to
 7. 4. Theevaporator according to claim 1, wherein an area of the second part isabout 5% to about 30% of a total area of the first part and the secondpart.
 5. An evaporator with a cool storage function, comprising: aplurality of refrigerant flow tubes each having a first side wall and asecond side wall opposite to the first side wall and provided to formspaces between the first side wall and the second side wall such thatthe first side wall of one of the plurality of refrigerant flow tubesfaces the second side wall of another of the plurality of refrigerantflow tubes, the spaces having a first part and a second part other thanthe first part; fins provided in the first part of the spaces; coolstorage material containers containing a cool storage material, each ofthe cool storage material containers having a longitudinal direction andincluding a third side wall and a fourth side wall opposite to the thirdside wall, the third side wall having a plurality of first convexportions arranged in the longitudinal direction, the fourth side wallhaving a plurality of second convex portions arranged in thelongitudinal direction, the cool storage material containers beingprovided in the second part of the spaces such that the first convexportions contact the first side wall of the one of the plurality ofrefrigerant flow tubes and the second convex portions contact the secondside wall of the another of the plurality of refrigerant flow tubes, aplurality of first paths formed between the third side wall and thefirst side wall of the one of the plurality of refrigerant flow tubes tobe arranged in the longitudinal direction, a plurality of second pathsformed between the fourth side wall and the second side wall of theanother of the plurality of refrigerant flow tubes to be arranged in thelongitudinal direction.
 6. The evaporator according to claim 5, whereinthe first convex portions are brazed to the first side wall of the oneof the plurality of refrigerant flow tubes and the second convexportions are brazed to the second side wall of the another of theplurality of refrigerant flow tubes.
 7. The evaporator according toclaim 5, wherein a number of the first part provided between the secondpart and the second part is 3 to
 7. 8. The evaporator according to claim5, wherein an area of the second part is about 5% to about 30% of atotal area of the first part and the second part.